Table 7. In Vitro methane production (ml/gm DDM) with rumen liquor of buffaloes fed different levels of TDN.

Substrate	Inoculum (% TDN in diet)			Mean	SEM	P Value
	70	85	100			substrate	Inoculum	sub * Ino
Hay
Maize hay	44.70	39.83	59.60	48.04	3.98	0.61	0.02	0.99
Oat hay	49.05	45.04	61.15	51.75
Berseem hay	44.07	40.61	54.02	46.23
Mean	45.94ab	41.83b	58.26a
Roughage
Wheat straw	41.94	55.12	63.81	53.62x	4.4	<0.001	0.24	0.32
Paddy straw	28.04	33.03	30.10	30.39y
Sugarcane bagasse	57.85	44.06	63.73	55.21x
Mean	42.61	44.07	54.15
Diet (concentrate: roughage ratio)
20:80	53.02	52.62	69.11	58.25	5.09	0.81	0.20	0.96
35:65	59.54	61.96	66.20	62.57
50:50	55.66	55.57	67.05	59.43
Mean	56.07	56.72	67.45

su ^abMeans with different superscripts in row differ significantly (P<0.05);

^xy Means with different superscripts in column differ significantly (P < 0.05);

sub * Ino = substrate*inoculum interaction